What I have seen is a confusion (perhaps intentional) between anti-semitism, and protesting Israel’s behavior since the Hamas attack in October.
Criticizing Israel’s response is not anti-Semitism- it is literally just criticizing the response.
Of course, a lot of criticism of Israel is rooted in antisemitism. But saying all criticism of Israel is antisemitic deflects legitimate criticism, and makes it harder to identify legitimate antisemitism.
Who is saying this? All I've heard are people on one side insisting that people are saying this, sounds like a straw man
1. https://www.congress.gov/118/bills/hres894/BILLS-118hres894i...
This is not the same as being critical of that state, being anti-Israel isn't antisemitic (except when it is, obviously), but nor is it anti-Zionism. Saying Netanyahu should be dragged before the Hague, that the international community should demand an immediate ceasefire or force a two-state solution, that Israel must uphold the right of return: none of these are anti-Zionism, nor antisemitic.
If your position is not that Israel must be destroyed, good, don't call yourself anti-Zionist though. If it is, then yes, that's antisemitic, or the word is meaningless.
Similarly, find another slogan besides "From the river to the sea", because that is, in fact, a call to ethnically cleanse all Jews from Israel. It has meant that since the establishment of Israel, and you don't get to wander in and say it means something different at this point. If you don't mean that, don't say it. Find literally any other way to express yourself.
The phrase was also used by the Israeli ruling Likud party as part of their 1977 election manifesto which stated "Judea and Samaria will not be handed to any foreign administration; between the Sea and the Jordan there will only be Israeli sovereignty."
So it hasn't always meant that, really.